* [PATCH] scsi:tcmu: switch tcmu completion path to work queue context
@ 2022-05-10 6:50 Guixin Liu
2022-05-10 12:21 ` kernel test robot
2022-05-10 15:05 ` kernel test robot
0 siblings, 2 replies; 3+ messages in thread
From: Guixin Liu @ 2022-05-10 6:50 UTC (permalink / raw)
To: bostroesser, martin.petersen; +Cc: linux-scsi, target-devel
Currently, tcmu do completion in uio_write context, the userspace
will wait until tcmu`s done synchronously, switch completion path to
work queue context for better performance.
Use tcmu + file to evaluate performance,
fio job: fio -filename=/dev/sdb -direct=1 -size=2G -name=1 -thread
-runtime=60 -time_based -rw=randwrite -numjobs=16 -iodepth=16 -bs=128k
Without this patch:
READ: bw=2775MiB/s (2910MB/s), 173MiB/s-174MiB/s
(181MB/s-183MB/s), io=163GiB (175GB), run=60001-60001msec
With this patch:
READ: bw=3333MiB/s (3495MB/s), 208MiB/s-209MiB/s
(218MB/s-219MB/s), io=195GiB (210GB), run=60001-60001msec
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
---
drivers/target/target_core_user.c | 151 +++++++++++++++++++++-----------------
1 file changed, 84 insertions(+), 67 deletions(-)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index fd7267b..0eb3396 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -168,6 +168,8 @@ struct tcmu_dev {
char dev_config[TCMU_CONFIG_LEN];
int nl_reply_supported;
+
+ struct work_struct complete_work;
};
#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
@@ -223,6 +225,7 @@ struct tcmu_tmr {
static atomic_t global_page_count = ATOMIC_INIT(0);
static struct delayed_work tcmu_unmap_work;
+struct workqueue_struct *tcmu_comp_wq;
static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
static int tcmu_set_global_max_data_area(const char *str,
@@ -1596,6 +1599,76 @@ static void tcmu_detach_hba(struct se_hba *hba)
hba->hba_ptr = NULL;
}
+static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
+{
+ struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
+ LIST_HEAD(cmds);
+ sense_reason_t scsi_ret;
+ int ret;
+
+ if (list_empty(&udev->qfull_queue))
+ return;
+
+ pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
+
+ list_splice_init(&udev->qfull_queue, &cmds);
+
+ list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
+ list_del_init(&tcmu_cmd->queue_entry);
+
+ pr_debug("removing cmd %p on dev %s from queue\n",
+ tcmu_cmd, udev->name);
+
+ if (fail) {
+ /*
+ * We were not able to even start the command, so
+ * fail with busy to allow a retry in case runner
+ * was only temporarily down. If the device is being
+ * removed then LIO core will do the right thing and
+ * fail the retry.
+ */
+ tcmu_cmd->se_cmd->priv = NULL;
+ target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
+ tcmu_free_cmd(tcmu_cmd);
+ continue;
+ }
+
+ ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
+ if (ret < 0) {
+ pr_debug("cmd %p on dev %s failed with %u\n",
+ tcmu_cmd, udev->name, scsi_ret);
+ /*
+ * Ignore scsi_ret for now. target_complete_cmd
+ * drops it.
+ */
+ tcmu_cmd->se_cmd->priv = NULL;
+ target_complete_cmd(tcmu_cmd->se_cmd,
+ SAM_STAT_CHECK_CONDITION);
+ tcmu_free_cmd(tcmu_cmd);
+ } else if (ret > 0) {
+ pr_debug("ran out of space during cmdr queue run\n");
+ /*
+ * cmd was requeued, so just put all cmds back in
+ * the queue
+ */
+ list_splice_tail(&cmds, &udev->qfull_queue);
+ break;
+ }
+ }
+
+ tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
+}
+
+static void tcmu_complete_work(struct work_struct *work)
+{
+ struct tcmu_dev *udev = container_of(work, struct tcmu_dev, complete_work);
+
+ mutex_lock(&udev->cmdr_lock);
+ if (tcmu_handle_completions(udev))
+ run_qfull_queue(udev, false);
+ mutex_unlock(&udev->cmdr_lock);
+}
+
static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
{
struct tcmu_dev *udev;
@@ -1634,6 +1707,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
xa_init(&udev->data_pages);
+ INIT_WORK(&udev->complete_work, tcmu_complete_work);
return &udev->se_dev;
}
@@ -1725,75 +1799,10 @@ static void tcmu_dev_kref_release(struct kref *kref)
call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
}
-static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
-{
- struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
- LIST_HEAD(cmds);
- sense_reason_t scsi_ret;
- int ret;
-
- if (list_empty(&udev->qfull_queue))
- return;
-
- pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
-
- list_splice_init(&udev->qfull_queue, &cmds);
-
- list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
- list_del_init(&tcmu_cmd->queue_entry);
-
- pr_debug("removing cmd %p on dev %s from queue\n",
- tcmu_cmd, udev->name);
-
- if (fail) {
- /*
- * We were not able to even start the command, so
- * fail with busy to allow a retry in case runner
- * was only temporarily down. If the device is being
- * removed then LIO core will do the right thing and
- * fail the retry.
- */
- tcmu_cmd->se_cmd->priv = NULL;
- target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
- tcmu_free_cmd(tcmu_cmd);
- continue;
- }
-
- ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
- if (ret < 0) {
- pr_debug("cmd %p on dev %s failed with %u\n",
- tcmu_cmd, udev->name, scsi_ret);
- /*
- * Ignore scsi_ret for now. target_complete_cmd
- * drops it.
- */
- tcmu_cmd->se_cmd->priv = NULL;
- target_complete_cmd(tcmu_cmd->se_cmd,
- SAM_STAT_CHECK_CONDITION);
- tcmu_free_cmd(tcmu_cmd);
- } else if (ret > 0) {
- pr_debug("ran out of space during cmdr queue run\n");
- /*
- * cmd was requeued, so just put all cmds back in
- * the queue
- */
- list_splice_tail(&cmds, &udev->qfull_queue);
- break;
- }
- }
-
- tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
-}
-
static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
-
- mutex_lock(&udev->cmdr_lock);
- if (tcmu_handle_completions(udev))
- run_qfull_queue(udev, false);
- mutex_unlock(&udev->cmdr_lock);
-
+ queue_work(tcmu_comp_wq, &udev->complete_work);
return 0;
}
@@ -3281,12 +3290,17 @@ static int __init tcmu_module_init(void)
INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
+ tcmu_comp_wq = alloc_workqueue("tcmu-comp-wq",
+ WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
+ if (!tcmu_comp_wq)
+ return -ENOMEM;
+
tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
sizeof(struct tcmu_cmd),
__alignof__(struct tcmu_cmd),
0, NULL);
if (!tcmu_cmd_cache)
- return -ENOMEM;
+ goto out_free_comp_wq;
tcmu_root_device = root_device_register("tcm_user");
if (IS_ERR(tcmu_root_device)) {
@@ -3335,6 +3349,8 @@ static int __init tcmu_module_init(void)
root_device_unregister(tcmu_root_device);
out_free_cache:
kmem_cache_destroy(tcmu_cmd_cache);
+out_free_comp_wq:
+ destroy_workqueue(tcmu_comp_wq);
return ret;
}
@@ -3347,6 +3363,7 @@ static void __exit tcmu_module_exit(void)
genl_unregister_family(&tcmu_genl_family);
root_device_unregister(tcmu_root_device);
kmem_cache_destroy(tcmu_cmd_cache);
+ destroy_workqueue(tcmu_comp_wq);
}
MODULE_DESCRIPTION("TCM USER subsystem plugin");
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] scsi:tcmu: switch tcmu completion path to work queue context
2022-05-10 6:50 [PATCH] scsi:tcmu: switch tcmu completion path to work queue context Guixin Liu
@ 2022-05-10 12:21 ` kernel test robot
2022-05-10 15:05 ` kernel test robot
1 sibling, 0 replies; 3+ messages in thread
From: kernel test robot @ 2022-05-10 12:21 UTC (permalink / raw)
To: Guixin Liu, bostroesser, martin.petersen
Cc: llvm, kbuild-all, linux-scsi, target-devel
Hi Guixin,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on mkp-scsi/for-next]
[also build test WARNING on v5.18-rc6 next-20220509]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Guixin-Liu/scsi-tcmu-switch-tcmu-completion-path-to-work-queue-context/20220510-145227
base: https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
config: x86_64-randconfig-a003-20220509 (https://download.01.org/0day-ci/archive/20220510/202205102014.hfkv5W49-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 18dd123c56754edf62c7042dcf23185c3727610f)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/08884eca055feed72186261c64dea07df464946e
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Guixin-Liu/scsi-tcmu-switch-tcmu-completion-path-to-work-queue-context/20220510-145227
git checkout 08884eca055feed72186261c64dea07df464946e
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/target/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> drivers/target/target_core_user.c:3336:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (!tcmu_cmd_cache)
^~~~~~~~~~~~~~~
drivers/target/target_core_user.c:3389:9: note: uninitialized use occurs here
return ret;
^~~
drivers/target/target_core_user.c:3336:2: note: remove the 'if' if its condition is always false
if (!tcmu_cmd_cache)
^~~~~~~~~~~~~~~~~~~~
drivers/target/target_core_user.c:3321:9: note: initialize the variable 'ret' to silence this warning
int ret, i, k, len = 0;
^
= 0
1 warning generated.
vim +3336 drivers/target/target_core_user.c
89ec9cfd3b644f Mike Christie 2017-11-28 3318
7c9e7a6fe11c8d Andy Grover 2014-10-01 3319 static int __init tcmu_module_init(void)
7c9e7a6fe11c8d Andy Grover 2014-10-01 3320 {
801fc54d5d943e Bryant G. Ly 2017-06-06 3321 int ret, i, k, len = 0;
7c9e7a6fe11c8d Andy Grover 2014-10-01 3322
7c9e7a6fe11c8d Andy Grover 2014-10-01 3323 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3324
af1dd7ff46824a Mike Christie 2017-11-28 3325 INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
9972cebb59a653 Mike Christie 2017-11-28 3326
08884eca055fee Guixin Liu 2022-05-10 3327 tcmu_comp_wq = alloc_workqueue("tcmu-comp-wq",
08884eca055fee Guixin Liu 2022-05-10 3328 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
08884eca055fee Guixin Liu 2022-05-10 3329 if (!tcmu_comp_wq)
08884eca055fee Guixin Liu 2022-05-10 3330 return -ENOMEM;
08884eca055fee Guixin Liu 2022-05-10 3331
7c9e7a6fe11c8d Andy Grover 2014-10-01 3332 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
7c9e7a6fe11c8d Andy Grover 2014-10-01 3333 sizeof(struct tcmu_cmd),
7c9e7a6fe11c8d Andy Grover 2014-10-01 3334 __alignof__(struct tcmu_cmd),
7c9e7a6fe11c8d Andy Grover 2014-10-01 3335 0, NULL);
7c9e7a6fe11c8d Andy Grover 2014-10-01 @3336 if (!tcmu_cmd_cache)
08884eca055fee Guixin Liu 2022-05-10 3337 goto out_free_comp_wq;
7c9e7a6fe11c8d Andy Grover 2014-10-01 3338
7c9e7a6fe11c8d Andy Grover 2014-10-01 3339 tcmu_root_device = root_device_register("tcm_user");
7c9e7a6fe11c8d Andy Grover 2014-10-01 3340 if (IS_ERR(tcmu_root_device)) {
7c9e7a6fe11c8d Andy Grover 2014-10-01 3341 ret = PTR_ERR(tcmu_root_device);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3342 goto out_free_cache;
7c9e7a6fe11c8d Andy Grover 2014-10-01 3343 }
7c9e7a6fe11c8d Andy Grover 2014-10-01 3344
7c9e7a6fe11c8d Andy Grover 2014-10-01 3345 ret = genl_register_family(&tcmu_genl_family);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3346 if (ret < 0) {
7c9e7a6fe11c8d Andy Grover 2014-10-01 3347 goto out_unreg_device;
7c9e7a6fe11c8d Andy Grover 2014-10-01 3348 }
7c9e7a6fe11c8d Andy Grover 2014-10-01 3349
4703b6252b338e Bodo Stroesser 2020-04-27 3350 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
7d7a743543905a Nicholas Bellinger 2017-03-18 3351 len += sizeof(struct configfs_attribute *);
4703b6252b338e Bodo Stroesser 2020-04-27 3352 for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
4703b6252b338e Bodo Stroesser 2020-04-27 3353 len += sizeof(struct configfs_attribute *);
4703b6252b338e Bodo Stroesser 2020-04-27 3354 for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
801fc54d5d943e Bryant G. Ly 2017-06-06 3355 len += sizeof(struct configfs_attribute *);
801fc54d5d943e Bryant G. Ly 2017-06-06 3356 len += sizeof(struct configfs_attribute *);
7d7a743543905a Nicholas Bellinger 2017-03-18 3357
7d7a743543905a Nicholas Bellinger 2017-03-18 3358 tcmu_attrs = kzalloc(len, GFP_KERNEL);
7d7a743543905a Nicholas Bellinger 2017-03-18 3359 if (!tcmu_attrs) {
7d7a743543905a Nicholas Bellinger 2017-03-18 3360 ret = -ENOMEM;
7d7a743543905a Nicholas Bellinger 2017-03-18 3361 goto out_unreg_genl;
7d7a743543905a Nicholas Bellinger 2017-03-18 3362 }
7d7a743543905a Nicholas Bellinger 2017-03-18 3363
4703b6252b338e Bodo Stroesser 2020-04-27 3364 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
7d7a743543905a Nicholas Bellinger 2017-03-18 3365 tcmu_attrs[i] = passthrough_attrib_attrs[i];
4703b6252b338e Bodo Stroesser 2020-04-27 3366 for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
4703b6252b338e Bodo Stroesser 2020-04-27 3367 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
4703b6252b338e Bodo Stroesser 2020-04-27 3368 for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
4703b6252b338e Bodo Stroesser 2020-04-27 3369 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
7d7a743543905a Nicholas Bellinger 2017-03-18 3370 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
7d7a743543905a Nicholas Bellinger 2017-03-18 3371
0a06d4309dc168 Christoph Hellwig 2015-05-10 3372 ret = transport_backend_register(&tcmu_ops);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3373 if (ret)
7d7a743543905a Nicholas Bellinger 2017-03-18 3374 goto out_attrs;
7c9e7a6fe11c8d Andy Grover 2014-10-01 3375
7c9e7a6fe11c8d Andy Grover 2014-10-01 3376 return 0;
7c9e7a6fe11c8d Andy Grover 2014-10-01 3377
7d7a743543905a Nicholas Bellinger 2017-03-18 3378 out_attrs:
7d7a743543905a Nicholas Bellinger 2017-03-18 3379 kfree(tcmu_attrs);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3380 out_unreg_genl:
7c9e7a6fe11c8d Andy Grover 2014-10-01 3381 genl_unregister_family(&tcmu_genl_family);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3382 out_unreg_device:
7c9e7a6fe11c8d Andy Grover 2014-10-01 3383 root_device_unregister(tcmu_root_device);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3384 out_free_cache:
7c9e7a6fe11c8d Andy Grover 2014-10-01 3385 kmem_cache_destroy(tcmu_cmd_cache);
08884eca055fee Guixin Liu 2022-05-10 3386 out_free_comp_wq:
08884eca055fee Guixin Liu 2022-05-10 3387 destroy_workqueue(tcmu_comp_wq);
7c9e7a6fe11c8d Andy Grover 2014-10-01 3388
7c9e7a6fe11c8d Andy Grover 2014-10-01 3389 return ret;
7c9e7a6fe11c8d Andy Grover 2014-10-01 3390 }
7c9e7a6fe11c8d Andy Grover 2014-10-01 3391
--
0-DAY CI Kernel Test Service
https://01.org/lkp
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] scsi:tcmu: switch tcmu completion path to work queue context
2022-05-10 6:50 [PATCH] scsi:tcmu: switch tcmu completion path to work queue context Guixin Liu
2022-05-10 12:21 ` kernel test robot
@ 2022-05-10 15:05 ` kernel test robot
1 sibling, 0 replies; 3+ messages in thread
From: kernel test robot @ 2022-05-10 15:05 UTC (permalink / raw)
To: Guixin Liu, bostroesser, martin.petersen
Cc: kbuild-all, linux-scsi, target-devel
Hi Guixin,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on mkp-scsi/for-next]
[also build test WARNING on v5.18-rc6 next-20220509]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Guixin-Liu/scsi-tcmu-switch-tcmu-completion-path-to-work-queue-context/20220510-145227
base: https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
config: x86_64-rhel-8.3-kselftests (https://download.01.org/0day-ci/archive/20220510/202205102245.Zg2ynlzX-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.2.0-20) 11.2.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.4-dirty
# https://github.com/intel-lab-lkp/linux/commit/08884eca055feed72186261c64dea07df464946e
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Guixin-Liu/scsi-tcmu-switch-tcmu-completion-path-to-work-queue-context/20220510-145227
git checkout 08884eca055feed72186261c64dea07df464946e
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/target/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
sparse warnings: (new ones prefixed by >>)
>> drivers/target/target_core_user.c:229:25: sparse: sparse: symbol 'tcmu_comp_wq' was not declared. Should it be static?
Please review and possibly fold the followup patch.
--
0-DAY CI Kernel Test Service
https://01.org/lkp
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-05-10 15:19 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2022-05-10 6:50 [PATCH] scsi:tcmu: switch tcmu completion path to work queue context Guixin Liu
2022-05-10 12:21 ` kernel test robot
2022-05-10 15:05 ` kernel test robot
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